**2.5 Dilution of concentrate to desirable EC**

EC is generally used to indicate the total concentration of ionized constituents in water (Rodríguez et al., 2006). The concentrates shall be diluted with the irrigation water until the desired electrical conductivity is reached for the crop to be established (usually at 1–2 dS m<sup>−</sup><sup>1</sup> ).

**79**

**Figure 4.**

*Nutritive Solutions Formulated from Organic Fertilizers DOI: http://dx.doi.org/10.5772/intechopen.89955*

The pH indicates the degree of acidity or basicity of the solutions and is relevant

<sup>2</sup><sup>−</sup>. The pH suitable for most plants in hydroponic systems

,

by the availability of plant nutrients. **Figure 4** shows pH behavior in sequential extractions, in both composts (bovine and poultry). The pH range was 7–7.8, neutral to alkaline, indicating the possible presence of ions such as Ca2+, Na+

*Electrical conductivity of concentrates obtained sequentially from poultry and bovine compost.*

is between 5 and 6 (Rodríguez et al., 2006), so organic nutrient solutions must be acidified that will partially eliminate carbonates and bicarbonates. Chemical or organic acids can be utilized; in the case of the test we conducted with bovine and poultry manure, the amount of sulfuric acid that we applied to lower pH from 7.4 to

With the measurement of EC and pH, hydroponics solutions can be assessed. Up to this point, it is possible to use the nutritive solution obtained in small- and

To produce higher biomass plants, for example, solanacea, cucurbitaceae, etc.,

it is recommended to have an analysis of the contents of essential elements in order to supplement in the organic nutrient solution, which can be very variable as shown in **Table 3**. The organic nutrient solutions are deficient in most essential elements when compared to known nutrient solutions. Therefore, it is necessary to supplement them with organic or inorganic sources, depending on the production

**2.6 Acidification of ONS**

**Figure 3.**

Mg2+, HCO3<sup>−</sup>, and CO3

system being worked.

**2.7 Nutrient supplementation**

6 per liter of ONS is 0.1 μL or 60 mL of acetic acid.

medium-sized plants, such as baby lettuces shown in **Figure 5**.

*pH of concentrates obtained sequentially from poultry and bovine compost.*

*Nutritive Solutions Formulated from Organic Fertilizers DOI: http://dx.doi.org/10.5772/intechopen.89955*

**Figure 3.**

*Urban Horticulture - Necessity of the Future*

**Rest time (h)**

**Fluid recovery (%)\*\***

**Volume recovery**

1:2 24 50 1 20.5 26.5 12.3 15.9 1:4 24 75 3 14 15 25.3 27 1:6 24 80 4.8 8 10 23 28.8 1:8 24 90 7.2 6 9 26 39 1:10 24 95 9.5 5.6 8 32 45.6 1:12 24 95 11.4 4 7 27.5 47.88 1.14 24 100 14 3 4.7 25.2 40 1:16 24 100 16 2.5 4 24 38.8

**Dilution ratio\***

**Extraction Dilution** 

**ratio\***

*Ratio solid material: volume of water applied.*

*Ratio solid material: volume of water applied*

**ART§§ Fluid** 

*Content of dissolved salts extracted (a single extraction with 24 h rest).*

**recovery (%)\*\***

*\*\*Volume of water recovering from applied; the remaining percentage is retained by the solid phase.*

*The mg of salts dissolved per liter of liquid concentrate (factor 0.6 was used to convert from dS m<sup>−</sup><sup>1</sup>*

**Volume recovery**

 1:2 48 50 1 20.5 26.5 12.3 15.9 1:2 96 60 1.4 6.1 15.5 4.4 13 1:2 144 80 1.6 2.6 5.67 2.5 5.44 4w 1:2 192 85 1.7 1.6 3.3 1.6 3.4 1:2 240 90 1.8 1.2 1.83 1.3 2 1.2 288 95 1.9 1.2 1.2 1.35 1.35 1.2 336 100 2 1.2 1 1.44 1.2 1.2 384 100 2 1.2 0.9 1.44 1

**78**

*\**

*\**

*§*

**Table 1.**

*§*

**Table 2.**

*each extraction).*

*§§Accumulated rest time*

from the fifth extraction between 1.2 and 1.8 dS m<sup>−</sup><sup>1</sup>

).

**2.5 Dilution of concentrate to desirable EC**

lished (usually at 1–2 dS m<sup>−</sup><sup>1</sup>

until the eighth extraction. The ion balance, between the solid and aqueous phase of the

*Salt content dissolved by sequential extraction (eight extractions in the same material with 48 h of rest between* 

EC is generally used to indicate the total concentration of ionized constituents in water (Rodríguez et al., 2006). The concentrates shall be diluted with the irrigation water until the desired electrical conductivity is reached for the crop to be estab-

mixtures, allows organic materials to be used as a source of nutrients for plants.

*\*\*Volume of water recovering from applied; the remaining percentage is retained by the solid phase.*

*The mg of salts dissolved per liter of liquid concentrate (factor 0.6 was used to convert from dS m<sup>−</sup><sup>1</sup>*

and continue with little variation

**Bovine Poultry Bovine Poultry**

**Bovine Poultry Bovine Poultry**

**dS m<sup>−</sup><sup>1</sup> §**

**Dissolved salts**

**mg L<sup>−</sup><sup>1</sup>**

**dS m<sup>−</sup><sup>1</sup> §**

**Dissolved salts**

 *to mg L<sup>−</sup><sup>1</sup> )*

**mg L<sup>−</sup><sup>1</sup>**

**Σ 26.33 43.3**

 *to mg L<sup>−</sup><sup>1</sup> )*

*Electrical conductivity of concentrates obtained sequentially from poultry and bovine compost.*
